In recent years, a portable recording and reproducing apparatus that can record and reproduce music and so forth, that has an internal hard disk drive, and that is miniaturized has come out. Such a portable recording and reproducing apparatus is connected to a personal computer so as to manage music data recorded in the apparatus.
For example, a lot of music data are stored in the internal hard disk drive of the personal computer. The music data forms a library. The personal computer forms a music server. Music data are ordinarily ripped from CDs (Compact Discs) or downloaded from a network using a music distributing system operated on a network such as the Internet.
The personal computer and the portable recording and reproducing apparatus are connected with a cable. Music data stored in the library of the personal computer are transferred to the portable recording and reproducing apparatus. The portable recording and reproducing apparatus records the transferred music data to the internal hard disk drive. When the user carries the portable recording and reproducing apparatus with him or her, he or she can enjoy the music data stored in the library of the personal computer anywhere for example outdoors.
Japanese Patent Laid-Open Publication No. 2002-108350 describes a structure for downloading music data from a server that stores a lot of music data and storing the downloaded music data in a user's terminal unit in accordance with a user's request.
On the other hand, as a recording medium to and from which digital audio data is recorded and reproduced, a mini disc (MD) of which a 64-mm diameter magneto-optical disc is contained in a cartridge has been widespread. The MD system uses ATRAC (Adaptive Transform Acoustic Coding) as a compressing system for audio data. Music data are managed with a U-TOC (User TOC (Table Of Contents). In other words, a recording area called U-TOC is formed on the inner periphery of a recordable area of the disc. In the current MD system, the U-TOC is management information that is rewritten in accordance with song order, recording, erasing, and so forth of tracks (audio tracks/data tracks). In addition, the U-TOC manages the start position, end position, and mode of each track and each part that composes a track.
Since the MD system uses a file managing method that is different from the FAT (File Allocation Table) file system that personal computers generally use, the MD system does not have compatibility with the data recording and managing system that general-purpose computers such as personal computers use. Thus, a system that uses a general-purpose managing system such as the FAT system that has high compatibility with personal computers has been proposed.
A portable recording and reproducing apparatus that uses as a recording medium a disc having compatibility with a personal computer may be connected to a music server using the foregoing personal computer. A library stored in the music server may be recorded to the disc.
The recording capacity of a disc of the conventional MD system is around 160 MB. It is thought that the same function as the portable recording and reproducing apparatus using the foregoing hard disk drive can be accomplished with a disc having compatibility with a conventional MD and having an increased recording capacity. To increase the recording capacity of a disc of the conventional MD system, it is necessary to improve the wave length of a laser and the numerical aperture (NA) of an optical head. However, their improvement has their limits. Thus, a system that increases the recording capacity using a technology of such as magnetic super resolution has been proposed.
However, when a personal computer is used as a music server and music data are transferred from the personal computer to the portable recording and reproducing apparatus, it is desired that the library of the personal computer be synchronized with the recorded contents on the portable recording and reproducing apparatus side. However, it is difficult to synchronize all the contents of the library of the music server with the recode contents of the portable recording and reproducing apparatus.
When the portable recording and reproducing apparatus uses a disc of the foregoing MD system as a recording medium, since the recording capacity on the portable recording and reproducing apparatus side is smaller than the capacity of the library, all the contents of the library cannot be synchronized with the portable recording and reproducing apparatus side.
In addition, when the library and the recorded contents on the portable recording and reproducing apparatus side are not automatically synchronized, whenever the portable recording and reproducing apparatus and the personal computer are connected, the user should perform the operation for synchronizing them.